This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Various abbreviations that appear in the specification and/or in the drawing figures are defined as follows:
3GPPthird generation partnership projectUTRAN universal terrestrial radio access networkEUTRANevolved UTRAN (LTE)LTElong term evolutionNode Bbase stationeNBEUTRAN Node B (evolved Node B)UEuser equipmentULuplink (UE towards eNB)CAZAC constant-amplitude zero auto-correlationDLdownlink (eNB towards UE)EPCevolved packet coreMMEmobility management entityS-GWserving gatewayMMmobility managementHOhandoverC-RNTIcell radio network temporary identifierPDUprotocol data unitPRBphysical resource blockPHYphysicalSNsequence numberRBradio bearerRLCradio link controlRRCradio resource controlRRMradio resource managementMACmedium access controlPDCPpacket data convergence protocolO&Moperations and maintenanceSDUservice data unitBWbandwidthCDMcode division multiplexingCQIchannel quality indicatorFDDfrequency division duplexFDMAfrequency division multiple accessFDMfrequency division multiplexingHARQhybrid automatic repeat requestACKacknowledgementNACKnegative ACKOFDMAorthogonal frequency division multiple accessSC-FDMAsingle carrier, frequency division multiple accessTDDtime division duplexTTItransmission time intervalPUCCHphysical uplink control channelPUSCHphysical uplink shared channelPRACHphysical random access channelACLRadjacent channel leakage ratioFSUflexible spectrum usageLAlocal areaRel. 8release 8SIBsystem information blockSRIscheduling request indicator
A communication system known as evolved UTRAN (E-UTRAN, also referred to as UTRAN-LTE or as E-UTRA) has been under development within the 3GPP. It has been specified that the DL access technique will be OFDMA, and the UL access technique will be SC-FDMA. In the above mentioned communication system, a basic uplink transmission scheme is a single-carrier transmission frequency division multiple access (SC-FDMA) with a cyclic prefix to achieve uplink inter-user orthogonality and to enable efficient frequency-domain equalization at the receiver side. Frequency-domain generation of the signal, sometimes known as DFT-spread orthogonal frequency division multiplexing (DFT S-OFDM), is assumed.
Within this uplink transmission, a physical uplink control channel (PUCCH) sub-frame structure carries UL control information such as ACK/NACK, CQI, and Scheduling Request Indicator (SRI) information. It has been understood that a PUCCH is used in the absence of UL data, and that the PUCCH may not be transmitted simultaneously with a physical uplink shared channel (PUSCH) from the same UE, as indicated in LTE specification Rel. 8. FIG. 1 shows the logical split between different PUCCH formats and the way the PUCCH is configured in accordance with the LTE specification. For more detailed information reference can be made to 3GPP TS 36.211 V8.2.0 (2008-03), 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation (Release 8).
The PUCCH sub-frame structure for UL control information signaling consists of two slots. Further, there may be seven SC-FDMA symbols, which are also referred to herein as “LBs” for convenience, defined per slot. A part of these LBs are used for reference signals such as pilot long blocks for coherent demodulation, while the remaining LBs are used for control and/or data transmission. An assumption has been that for the PUCCH, the multiplexing within a physical resource block (PRB) is performed using code division multiplexing (CDM), whereas a localized frequency division multiplexing (FDM) is used for other different resource blocks. In the PUCCH the bandwidth of one control and pilot signal always corresponds to one PRB.